The RhoA-mDia1 Signaling Pathway Is Required For Cyclic Strain-induced Cytoskeletal Rearrangement Of Human Periodontal Ligament Cells

Objective: The effect of orthodontic force on the teeth,making the teeth move,the fundamental mechanism of tooth movement is the remodeling of periodontal tissue,including the remodeling of periodontal membrane,The orthodontic force is transmitted through the teeth to the human periodontal ligament cells,which is the main effector cells in the periodontal membrane,which causes the changes of the biological function of the cells,For example: cell migration,cell apoptosis,cell skeleton reconstruction.The purpose of this study was to study the effects of orthodontic force on the cytoskeleton rearrangement of human periodontal ligament cells,and to clarify the role of Rho A-m Dia1 signaling pathway in the cytoskeleton rearrangement of human periodontal ligament cells induced by strain.Methods: Obtaining healthy human premolars extracted for orthodontics therapy.Materials and primary culture on the super clean bench,Identification of Human Periodontal Fibroblast Cells by immunohistochemistry.making cyclic strain on human periodontal igament fibroblasts inoculated to Bioflex 6-well culture plate by FX-5000 T cell strain loading system.The morphological changes of cells were observed by inverted microscope,and the changes of cytoskeleton were observed by confocal microscopy;Using Western blot method to detect the change of Rho-GDI?,m Dia1 and Rho and profilin-1 proteins;using co-immunoprecipitation to detect the combination of the m Dia1 and Rho A.The effect of Overexpression and silencing of Rho-GDI? protein on the Rho A-m Dia1 pathway protein and cytoskeleton rearrangement was observed.Results: The morphology of cultured cells became slender,spindle shaped by inverted phase contrast microscope,Immunohistochemical identification showed that the negative control group and keratin staining was negative,but the vimentin staining was positive;Compared with static group,inverted microscope showed cyclic strain induced human periodontal ligament cell cytoskeleton rearrangement,cells gradually palisade arranged parallel to each other and arranged in vertical to the tension direction of distraction.The western blot show the expression levels of Rho A-GTP,profilin-1 protein and the the combination of Rho A and m Dia1 are increased,whereas the expression levels of Rho-GDI? is reduced compared with the static control group.On the contrary,the profilin-1 protein expression and cytoskeletal reorganization under cyclic strain can decrease due to the overexpression of Rho-GDI?,while ho-GDI? si RNA transfection has the opposite effect on the h PDLCs.Conclusion: Our results demonstrate that Rho A-m Dia1 signaling pathway is involved in the cytoskeletal rearrangement of h PDLCs induced by cyclic strain.